The problem of relapse continues to plague public health efforts to reduce the prevalence of cigarette smoking. Recent studies indicate a large percentage of individuals attempting smoking cessation lapse to smoking within a matter of days, and very few of these individuals are able to recover to achieve abstinence from smoking. Current models of relapse devote insufficient attention to this phenomenon of early lapse and results of studies attempting to relate severity of nicotine withdrawal symptoms to short-term smoking cessation outcomes have been equivocal. Thus, there is a need for an expanded perspective on early lapse. In the current application, we focus on the interactive role of trait levels of negative affect, affect-related withdrawal symptoms, and one's threshold for tolerating the physical and psychological distress that occurs in the context of a smoking cessation attempt (i.e., distress tolerance). Conceptualized within a threshold model of early smoking lapse, each smoker has a specific affective threshold at which they point they will return to smoking. The threshold of each of smoker is variable with some exhibiting high tolerance for distress and others exhibiting low tolerance for distress. Thus, whether a given level of negative affect leads to a smoking lapse may be moderated, in part, by an individual's willingness and ability to tolerate that discomfort. Based upon this model, we predict that trait levels of negative affect, affective reaction to nicotine deprivation, and distress tolerance will each uniquely predict smoking lapse. Furthermore, distress tolerance will moderate the effects of negative affect on the likelihood of smoking lapse. To test this model in a sample of 120 adult smokers, we will examine persistence on physical and psychological stressors, trait levels of negative affect, and negative affect-related withdrawal symptoms on an experimental 12-hr abstinence session as prospective predictors of early smoking lapse following standard individual therapy for smoking cessation aided by nicotine replacement therapy. Findings from this investigation should result in improved methods of identifying smokers at-risk for early lapse, so that they may be targeted for nicotine dependence treatments that will meet their specific needs. Results of this study also should have direct implications for the development of novel pharmacological and behavioral treatments for nicotine dependence for this particularly vulnerable group of smokers.